Systems and methods of power output measurement

ABSTRACT

The present invention pertains to systems and methods of individual power output measurement. One embodiment relates to a pressure sensing device configured to be mounted on the bottom surface of a shoe. The device includes a sensor, a wireless communication system, a housing, and a mounting system. A second embodiment relates to a direct power measurement system including a pressure sensing device, a computer module, and a display module. In a bicycling application of the system, the device is mounted on the bottom surface of a shoe so as to measure applied pressure between at least one of the rider&#39;s shoe and corresponding bicycle pedal. The computing module mathematically converts the measured pressure as a function of time to a value of power exerted by the rider. In addition, the computing module may utilize the measured pressure as a function of time to compute the rider&#39;s cadence (pedal revolutions per unit of time). Various well-known communication systems such as RF may be integrated within the device and computing module to facilitate data transmission. Similar systems may be used to calculate an individual&#39;s power output during other activities including but not limited to running, rowing, walking, etc. A third embodiment relates to a method for calculating individual power output during an athletic activity. The method includes sensing pressure at a particular location, calculating or computing power, and displaying power.

RELATED APPLICATIONS

This application claims priority to U.S. provisional application Ser. No. 60/678,887 filed May 6, 2005.

BACKGROUND

1. Field of the Invention

The present invention relates to systems and methods of power output measurement. In particular the present invention relates to a power measurement device.

2. Background of the Invention and Related Art

Endurance athletes utilize various metrics to measure their performance and chart their workouts. These metrics are recorded and analyzed both during and after workouts. For example, interval type workouts typically involve multiple sets of intense activity, semi-intense activity, and rest. The intense activity may be characterized by a range of metrics which correlate to the desired intensity for a particular athlete. Likewise, the rest or semi-intense activity periods may be characterized by a range or metrics which correlate to the desired restful state for a particular athlete. One common form of metric measurement includes an athlete's heart rate. An athlete can utilize specific heart rate ranges to obtain desired intensity or restful states. Various well known methodologies exist for analyzing heart rate including the use of VO_(2max), maximum heart rate, age, etc. However, it has been determined that heart rate alone is not necessarily an accurate assessment of the amount of work an individual is exerting at any given time. For example, as an athlete improves or increases fitness, his/her max heart rate may increase while relative working heart rate for a particular activity may remain constant. In this case, conventional heart rate measurement will not accurately identify an athlete's increased performance. Therefore, it is necessary to utilize other metric measurements or combinations of metrics to accurately measure an athlete's work load during a particular activity.

One particularly useful metric measurement involves calculating the amount of power or work an athlete is generating as a function of time. An increase in power output directly translates to an increased athletic performance. Likewise, a decrease in power output translates to a decreased athletic performance. The measurement of instantaneous power has become popular for certain activities, including cycling. Power output has been determined to be a more accurate measurement of an athlete's performance and is therefore a more useful metric for analysis and improvement.

Unfortunately, it is difficult to accurately measure an athlete's power output. Power is a function of force, and many sports involve the application of force in a variety of directions. In addition, few athletes are willing to wear or equip heavy force measurement devices. In cycling, well known existing devices have attempted to calculate power output as a function of pedal cadence. This measurement scheme is inherently inaccurate because the power necessary to pedal at a particular cadence depends tremendously upon the surface over which the bicycle is traveling. For example, a steep hill requires more power per pedal stroke than a flat or downhill grade. Likewise, systems that attempt to extrapolate power measurements from heart rate are inherently flawed because they do not account for the increased power output that often accompanies an increase in fitness.

Accordingly, there is a need in the industry for an efficient and accurate system of power output measurement.

SUMMARY OF THE INVENTION

The present invention pertains to systems and methods of individual power output measurement. One embodiment relates to a pressure sensing device configured to be mounted on the bottom surface of a shoe. The device includes a sensor, a wireless communication system, a housing, and a mounting system. A second embodiment relates to a direct power measurement system including a pressure sensing device, a computer module, and a display module. In a bicycling application of the system, the device is mounted on the bottom surface of a shoe so as to measure applied pressure between at least one of the rider's shoe and corresponding bicycle pedal. The computing module mathematically converts the measured pressure as a function of time to a value of power exerted by the rider. In addition, the computing module may utilize the measured pressure as a function of time to compute the rider's cadence (pedal revolutions per unit of time). Various well-known communication systems such as RF may be integrated within the device and computing module to facilitate data transmission. Similar systems may be used to calculate an individual's power output during other activities including but not limited to running, rowing, walking, etc. A third embodiment relates to a method for calculating individual power output during an athletic activity. The method includes sensing pressure at a particular location, calculating or computing power, and displaying power.

These and other features and advantages of the present invention will be set forth or will become more fully apparent in the description that follows and in the appended claims. The features and advantages may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. Furthermore, the features and advantages of the invention may be learned by the practice of the invention or will be obvious from the description, as set forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the manner in which the above-recited and other advantages and features of the invention are obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

FIG. 1 illustrates an exploded view of a pressure sensing device configured to be mounted on a shoe in accordance with one embodiment of the present invention;

FIG. 2 illustrates a perspective view of a biking shoe with a pressure sensing device attached in accordance with a power output measuring system embodiment of the present invention;

FIG. 3 illustrates a perspective view of the biking shoe of FIG. 2, further illustrating the exploded attachment of a sensor cover;

FIG. 4 illustrates a perspective view of the assembled pressure sensing device and sensor cover illustrated in FIGS. 2 and 3;

FIG. 5 illustrates a perspective view of a pressure sensing device incorporated into a sock in accordance with an alternative device embodiment of the present invention; and

FIG. 6 illustrates a perspective view of one embodiment of a power output measuring system for a bicycle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention pertains to systems and methods of individual power output measurement. One embodiment relates to a pressure sensing device configured to be mounted on the bottom surface of a shoe. The device includes a sensor, a wireless communication system, a housing, and a mounting system. A second embodiment relates to a direct power measurement system including a pressure sensing device, a computer module, and a display module. In a bicycling application of the system, the device is mounted on the bottom surface of a shoe so as to measure applied pressure between at least one of the rider's shoe and corresponding bicycle pedal. The computing module mathematically converts the measured pressure as a function of time to a value of power exerted by the rider. In addition, the computing module may utilize the measured pressure as a function of time to compute the rider's cadence (pedal revolutions per unit of time). Various well-known communication systems such as RF may be integrated within the device and computing module to facilitate data transmission. Similar systems may be used to calculate an individual's power output during other activities including but not limited to running, rowing, walking, etc. A third embodiment relates to a method for calculating individual power output during an athletic activity. The method includes sensing pressure at a particular location, calculating or computing power, and displaying power. While embodiments of the present invention are directed at systems and methods of power output measurement, it will be appreciated that the teachings of the present invention are applicable to other areas.

The following terms are defined as follows:

Metric—A numerical value relating to a particular measurement. For example, speed, heart rate, power output, cadence, stroke, etc.

Pressure Sensor—A device configured to measure the amount of applied pressure at a particular point or area, wherein the measured pressure is converted into an electrical data signal.

Shoe—An article that covers a user's foot and possibly a portion of a user's lower leg. A shoe may be composed of both flexible and rigid materials and combinations thereof. A shoe may be designed to achieve specific performance characteristics consistent with a particular sport. For example, a cycling shoe is generally rigid so as to maximize force transfer between a rider and a bicycle.

Wireless communication system—Any system capable of transmitting data wirelessly between two or more points. For example, a radio transmitter may be used to convert and transmit electrical signals across a radio frequency to a radio receiver.

Mounting system—An attachment system for mechanically coupling one item to another. For example, a mounting system is used in accordance with embodiments of the present invention to couple a pressure sensing device to a user and/or an athletic article.

Reference is initially made to FIG. 1, which illustrates an exploded view of a pressure sensing device configured to be mounted on a shoe in accordance with one embodiment of the present invention, designated generally at 100. The pressure sensing device 100 includes a sensor 110, a housing 120, a wireless communication system 190, and a mounting system 180 (shown in both FIGS. 1 and 3). The sensor 110 further includes a top sensor housing 104, a sensor plate 106, a bottom sensor housing 108, and an electrical coupler 102. The illustrated sensor plate 106 is a force sensing resistor (FSR). Force sensing resistors are uniquely suited for athletic force measurement due to their dimension and weight characteristics. The electrical resistance at the electrical coupler 102 of the sensor plate 106 is directly related to the amount of pressure or force applied upon the FSR. The sensor 110 further includes a plurality of holes 112 which facilitate a portion of the mounting system 180, as illustrated in FIG. 3. The holes 112 may be arranged to be consistent with a universal 3-hole Look™ style mount. The top and bottom sensor housing 104, 108 effectively cover the majority of the sensor plate 106. This covering system protects the sensor plate 106 from damage without substantially affecting the measurement of applied pressure. The covering or sandwiching arrangement of the top sensor housing 104, sensor plate 106, and bottom sensor housing 108 allows pressures to be directly transmitted from one of the top and bottom sensor housing 104, 108 to the sensor plate 106. However, pressure can only be sensed between two objects. For example, if a force is applied upon the top sensor housing 104, the bottom sensor housing must be coupled to another object to oppose the force such that pressure can be sensed. The process of pressure measurement will be described in more detail below.

The housing 120 is configured to protect portions of the device that may otherwise be damaged by exposure or incidental contacts. The illustrated housing 120 includes an enclosure 124, a cap 122, an o-ring 128, and a cover 126. The enclosure 124 provides a cavity in which portions of the wireless communication system 190 may be housed. In addition, the enclosure 124 and the cap 122 facilitate portions of the mounting system 180 that allow the device 100 to be coupled to articles for use in measuring particular pressure values. The o-ring 128 and cover 126 are positioned to cover and seal a back opening of the enclosure 124. The back opening of the enclosure, allows for access and assembly of the printed circuit board 194.

The illustrated mounting system 180 includes two attachment members 182 configured to extend through a portion of the housing 120 for the purpose of attaching the device to an article (not shown). In addition, the mounting system 180 includes three other attachment members 184 (illustrated in FIG. 3) which extend through a sensor cover 152 and the sensor 110 for further attachment to an article. The illustrated mounting system 180 may further include the use of adhesive or other chemical coupling system to be used in place of or in conjunction with the attachment members 182. In the illustrated embodiments of FIGS. 2-4, the article is a shoe 205. Various other mounting systems may be used in accordance with the present invention including quick-release type systems that would allow for efficient attachment and release of the device 100 to an article.

The wireless communication system 190 is electrically coupled to the sensor 110 via the electrical coupler 102. The wireless communication system 190 is configured to wireless transmit data corresponding to the pressure applied upon the sensor 110. The illustrated wireless communication system 190 further includes a printed circuit board 194 and a power supply 192. The power supply may include batteries that are configured to be rechargeable without removal from the device 100. The printed circuit board 194 includes various electrical components including but not limited to a transmitter, an antenna, a processor, a DC converter, etc. The printed circuit board 194 may further include a microprocessor that performs one or more mathematical computations on the measured pressure such as a mathematical conversion to measure power. The printed circuit board 194 further includes a coupler for facilitating the electrical coupling with the sensor 110. The transmitter may be configured to transmit the data utilizing any wireless data medium including but not limited to radio frequency, microwave, magnetic coupling, infrared, etc. In addition, the printed circuit board 194 is shaped to conform to the internal dimensions of the housing 124 and to facilitate the electrical coupling with the sensor 110. In addition, the power supply 192 and corresponding circuitry on the printed circuit board 194 are arranged in a manner that will also conform to the internal dimensions of the housing 124.

One embodiment of the electrical operation of the pressure sensing device 100 and accompanying power measurement system (not illustrated) is described for demonstrative purposes. The sensor 110 is powered by a constant current source such as the power supply 192. In response to pressure, the sensor 110 produces a time varying voltage that is amplified by a standard op-amp amplifier. An output voltage from the sensor 110 is split into three streams that are eventually transmitted to a microcontroller. The first stream computes RMS, the second stream produces a pulse stream that is proportional to the frequency of the output voltage, and the third stream is directly transmitted to the microcontroller. The microcontroller samples the three streams every 1/10 of a second and counts the number of pulses that occur every second after a sensed pressure. This data is then buffered as 10 bit data and wirelessly transmitted using a Zigbee™ RF standard. A receiver module may receive the signal and display the data on an LCD display screen. The receiver module may also be configured to receive multiple signals from a plurality of pressure sensing devices. Likewise, the wireless components may form a mesh network that allow for various devices to interface with one another. In addition, the receiver module may be equipped with a USB microcontroller to facilitate directly interfacing and transmitting data to a personal computer. Various other electrical configurations may be utilized in accordance with the present invention.

Reference is next made to FIGS. 2-4, which illustrate a perspective view of a biking shoe with a pressure sensing device attached in accordance with a power output measuring system embodiment of the present invention, designated generally at 200. The biking shoe may also be referred to as an athletic article. The illustrated shoe 205 is a cycling shoe, and the illustrated pressure sensing device 100 is the pressure sensing device 100 described with reference to FIG. 1. However, other shoe and pressure sensing device combinations may be practiced in accordance with the present invention. The sensor cover 152 is shaped three dimensionally to cover the exposed surfaces of the sensor 110. In addition, the sensor cover 152 includes a plurality of holes positioned to correspond to the holes of the sensor 110. Three attachment members 184 may then be extended through the sensor cover 152, the sensor 110, and into a receiving boss on the shoe 205, as part of the mounting system 180. Various seals and couplers may also be utilized to prevent water or debris from contacting the sensor. It should be noted that the sensor cover 152 must be coupled to the shoe 205 in a manner that allows for effective force transfer so as to not affect the measured pressure upon the sensor 110. A cleat or bicycle pedal attachment system may be incorporated into the sensor cover 152 or other portion of the device 100 so as to minimize weight. In addition, various calibrations may be necessary to optimize the performance of a particular shoe and pressure sensing device combination.

Reference is next made to FIG. 5, which illustrates a perspective view of a pressure sensing device 310 incorporated into a sock 305 in accordance with an alternative device embodiment of the present invention, designed generally at 300. The sock 305 is an alternative article which may be used for attachment of a pressure sensing device 310 in accordance with the systems and methods of the present invention. Various sports such as cycling, running, etc. require athletes to exert forces by their feet onto the ground or another athletic article such as a bicycle pedal. Therefore, the measurement of pressure at the bottom of a user's leg 315 may be applicable in determining power output during particular athletic activities. The pressure sensing device 310 is positioned at approximately the ball of the user's foot for the most efficient measurement of exerted forces by a user. In addition, the bottom of the sock 305 may include a rigid or semi-rigid surface to assist in coupling and stabilization of the pressure sensing device 310 in relation to the remainder of the sock 305. Various pressure sensing devices 310 may be used in conjunction with a sock including but not limited to the pressure sensing device illustrated and described with reference to FIG. 1.

Reference is next made to FIG. 6, which illustrates a perspective view of one embodiment of a power output measuring system for a bicycle, designated generally at 400. The power measurement system includes pressure sensing devices 410 and a computing and display module 405. The pressure sensing devices 410 are positioned in a particular location between the rider 415 or user's shoe and the pedals of the bicycle. This location has been determined to effectively measure pressure for purposes of calculating power output of the user while cycling. The bicycle further includes a frame 420, two tires 425, a seat 430, and a pair of pedals 435. The pressure sensing devices 410 wirelessly transmit data to the computing and display module relating to the pressure and/or power output applied at each of the pressure sensing devices 410. It should be noted that alternative embodiments may utilize a single pressure sensing device 410 between only one of the rider's 415 shoes and pedal 435. The computing/display module 405 is positioned on the handlebars of the bicycle but may also be positioned on the user's wrist or the bicycle stem to allow for efficient visual recognition by the user. The computing/display module 405 calculates power output of the user while cycling by receiving data from the pressure sensing devices 410 and converting or computing power in a display format such as a numerical metric or visual graph. It has been determined that the pressure measurements at the particular locations will exhibit a cyclic characteristic that is consistent with the pedal cadence and can therefore be used to calculate and display cadence in addition to power output. Although illustrated for purposes of measuring a cyclist's power output, the teachings of the illustrated system are applicable to other athletic activities.

A further embodiment (not illustrated) refers to a method of dynamically bracketing a metric during an athletic activity. An athlete who is performing an athletic activity may often wish to hold a metric within a particular range so as to maximize performance. However, this range may not be quantifiable before or after the athletic activity. Therefore, it is necessary to dynamically bracket the metric during the athletic activity. The method includes continuously monitoring at least one metric associated with the athlete's athletic performance or exertion level. For example, heart rate and power output may be continuously monitored and displayed to the athlete. Upon recognition of a useful situation, the athlete makes a bracket request to a computer module. The method then assigns a bracket or set of metric values corresponding to a set of values substantially centered around the measure metric value at the particular time at which the bracket request was received. Various well known electrical systems and methods may be employed in the execution of this method in accordance with the present invention.

Thus, as discussed herein, the embodiments of the present invention relate to a system of power output measurement. The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope. 

1. An athletic activity pressure sensing device comprising: a pressure sensor disposed in a particular location to receive pressure during an athletic activity, wherein the particular location is related to the athletic activity, and wherein the pressure sensor is configured to convert received pressure into electrical data; a wireless communication system electrically coupled to the pressure sensor and configured to wirelessly transmit the electrical data; a housing substantially enclosing the wireless communication system while facilitating the electrical coupling between the pressure sensor and the wireless communication system; and a mounting system configured to mechanically couple the athletic activity pressure sensing device to an athletic article in a manner that facilitates the disposal of the pressure sensor at the particular location.
 2. The device of claim 1, wherein the pressure sensor further includes a top housing, a sensor plate, a bottom housing, and an electrical coupler, and wherein the top housing, sensor plate, and bottom housing include a plurality of holes to facilitate a portion of the mounting system.
 3. The device of claim 1 further including a power supply that provides electrical power to at least one of the pressure sensor and the wireless communication system.
 4. The device of claim 1, wherein the athletic activity is cycling, the athletic article is a shoe, and the particular location is between the athletic article and a pedal of a corresponding bicycle.
 5. The device of claim 1, wherein the athletic article is coupled to a portion of a user's body that is primarily utilized in the performance of the athletic activity.
 6. The device of claim 1, wherein the wireless communication system is disposed on a printed circuit board mechanically coupled and housed within the housing, and wherein the wireless communication system includes a power supply.
 7. A system for measuring athletic power output during an athletic activity comprising: a pressure sensing device configured to measure pressure at a particular location, wherein the particular location is related to the athletic activity, and wherein the pressure sensing device converts the measured pressure into data and wirelessly transmits the data; a computing module configured to wirelessly receive the data and mathematically convert the data into a value of power output according to a specific algorithm; and a display module configured to display the power output value, wherein the display module is disposed in a second location that allows a user to view the display during the athletic activity.
 8. The system of claim 7, wherein the pressure sensing device is mechanically coupled to an athletic article that is coupled to a portion of a user's body that is primarily utilized in the performance of the athletic activity.
 9. The system of claim 7, wherein the pressure sensing device comprises: a pressure sensor disposed in a particular location to receive pressure during the athletic activity, wherein the particular location is related to the athletic activity, and wherein the pressure sensor is configured to convert received pressure into electrical data; a wireless communication system electrically coupled to the pressure sensor and configured to wirelessly transmit the electrical data; a housing substantially enclosing the wireless communication system while facilitating the electrical coupling between the pressure sensor and the wireless communication system; and a mounting system configured to mechanically couple the pressure sensing device to an athletic article in a manner that facilitates the disposal of the pressure sensor at the particular location.
 10. The method of claim 7, wherein the computing module is housed within the pressure sensing device so as to directly calculate power output at the particular location.
 11. The method of claim 7, wherein the athletic activity is cycling, the particular location is between a shoe and a pedal of a corresponding bicycle, and the second location is on the handlebars of the bicycle.
 12. The method of claim 7, wherein the computer module further includes a wireless receiver, a power supply, and a processor.
 13. The method of claim 7, wherein the computer module and display module are housed as a single unit.
 14. A method for calculating individual power output during an athletic activity comprising the acts of: sensing pressure at a particular location, wherein the particular location is related to the athletic activity; computing power as a function of time through the application of a particular mathematical algorithm; and displaying power to a user in a manner that allows the user to view the power while performing the athletic activity.
 15. The method of claim 14, wherein the act of sensing pressure at a particular location further includes the acts of: receiving a force at the particular location; measuring the received force; converting the measured force into electrical data; and transmitting the electrical data.
 16. The method of claim 14, wherein the act of computing power as a function of time through the application of a particular mathematical algorithm further includes the acts of: receiving data corresponding to the sensed pressure; and calculating power as a function of time.
 17. The method of claim 16, wherein the act of calculating power is performed continuously so as to continuously update the computed power.
 18. The method of claim 14, wherein the athletic activity is cycling, the particular location is between the athletic article and a pedal of a corresponding bicycle, and the power is displayed on an appropriately accessible area of the corresponding bicycle.
 19. A method of dynamically bracketing a metric during an athletic activity comprising the acts of: providing a user performing an athletic activity that affects at least one of heart rate, power output, muscle fatigue, and body heat; continuously measuring a metric during the performance of the athletic activity, wherein the metric is associated with at least one of the performance level of the user at the athletic activity and the exertion level of the user; receiving a bracket request from the user at a particular time during the performance of the athletic activity; assigning a bracket of metric values corresponding to a set of values substantially centered around the measured metric value at the particular time at which the bracket request was received.
 20. The method of claim 11, wherein the metric is heart rate.
 21. The method of claim 11, wherein the metric is power output.
 22. The method of claim 11 further includes the act of alerting the user if the user falls outside of the assigned bracket of metric values. 